Well, not really. Within a Data Pump SQL project it is called [dbo].[Last] and is primarily intended to be queried by third-party applications, like SCADA, EP, CEP or reporting tools. The table contains only one row with the latest serial number and the time-stamp from the [dbo].[PartData] table. Here is a typical example:
| ID | Val | TimeUTC | TimeLoc |
|---|---|---|---|
| 1 | 200805151007 | 2008-05-15 14:30:01 | 2008-05-15 10:30:01 |
The table structure may vary, depending on the project. Time column in UTC allows for applications outside of the time zone.
| Column Name | Data Type | Description |
|---|---|---|
| ID | int | ID column for this table; always 1 (one row only). |
| Val | bigint | Serial number of the last entry from [dbo].[PartData]. |
| TimeUTC | datetime | Time-stamp of the last entry in UTC (GMT). |
| TimeLoc | datetime | Optional. Local time of the last entry. |
The “third-party” application should query the [dbo].[Last] table and determine if there were any changes to the [dbo].[PartData] table since the last query.
SELECT [Val], [TimeLoc]
FROM [dbo].[Last] WHERE ID = 1;
Once a change is detected, it is OK to query the [dbo].[PartData] table.
/* Time of the last query */
DECLARE @LastTime datetime;
SET @LastTime = '2008-05-15 14:30:01';
--
/* Query the table */
SELECT *
FROM [dbo].[PartData]
WHERE [RecordDate] >= @LastTime;